Machine for slotting commutators



Dec. 27, 1955 K. H. WEBER 2,728,269

MACHINE FOR SLOTTING COMMUTATORS Filed Dec. '7, 1951 m '5 Sheets-Sheet l lf 's INVEWTOR. Karl H. Weber BY $47, uw?

ATTORNEYS Dec. 27, 1955 K. H. WEBER 2,728,269

MACHINE FOR SLOTTING COMMUTATORS Filed De'c. 7, 1951 5 Sheets-Sheet 2 ATTORNEYS f Dec. 27, 1955 K, H, WEBER MACHINE FOR SLOTTING COMMUTATORS 5 Sheets-Shea?l 5 Filed Deo. 7, 1951 INVENTOR. Karl H. Weber BY g da Ziff! Dec. 27, 1955 K. H. WEBER MACHINE FOR sLoTTING COMMUTATORS 5 Sheets-Sheet 4 Filed Dec. 7, 1951 IN VEN TOR. Kar/ H. Web er /TTORNE'YS 2 Dec. 27, 1955 K, H, WEBER 2,728,269

MACHINE FOR SLOTTING COMMUTATORS Filed Dec. 7, 1951 5 Sheets-Sheet 5 E INVENTOR. Kar/ H. Weber BY f United States Patent C)F MACHNE FOR SLGTTING COMR'IUTATGRS Karl H. Weber, Toledo, @his i Application December 7, 1951, Serial No. 269,360

10 Claims. (Cl. 90--15.i)

This invention relates to machines for undercutting the mica between the segments of a commutator, more particularly to a semi-automatic machine which will automatically undercut a complete commutator after being loaded manually thereon.

Mica undercutting machines in the past have been unsatisfactory for use in mass production lines due to the tediousness of the manual operations, particularly in that eye strain was rapidly developed by the operator during working. Furthermore, the machine could not be made semi-automatic because the indexing was a dicult problem which had not been satisfactorily solved for the reason that the commutators were not absolutely uniform in form or dimension. The width of the commutator bars varies considerably, also the thickness of the mica insulating spacers is not absolutely uniform even in one commutator, nor are the commutator bars always parallel with the axis of the shaft, so that a slight angularity develops which aggravates the problem of cutter alignment and the longitudinal movement of the cutter,-

along the slots of the commutator. It often developed that the cutter would leave the mica entirely and cut a slot into the adjacent commutator bar.

The present invention contemplates the provision of a machine which will obviate these diculties of the prior art. The machine is manually loaded with single commutators usually a part of a completely-wound armature, with the operation being automatic thereafter to completely undercut all the relatively frangible mica in be` tween the metallic segments of a commutator by a rotating cutter. The cutter is controlled by the conditions found in the individual commutators wherein it is guided by the substantially parallel sides of the commutator seg ments during the cutting operation, with the whole armature including the commutator, suspended in floating condition about the axis of the shaft in live centers cooperating with the ends of the shaft, so that the commutator accommodates itself to the cutter.

It is, therefore, a principal object of this invention to provide a semiautomatic machine for undercutting the mica insulation between the segments of an armature commutator.

It is a further object of this invention to provide an undercutting machine for commutators wherein the cutter is guided and controlled by the conditions in the commutator with the commutator being freely suspended for rotation about its longitudinal axis.

It is a further object of this invention to provide an undercutting machine for commutators wherein a rotating cutter is held in fixed position with means provided to reciprocate the commutator along its longitudinal axis to move the rotating cutter along the slots and back, the commutator being suspended to allow free rotation about its longitudinal axis, so that the commutator can accommodate itself to the cutter whereby the cutter closely follows the slots.

It is a further object of this invention to provide an indexing device for a commutator undercutting machine 2,728,269 Patented Dec. 27, 1955 ICC l?. which will engage the just-cut slot in the commutator to move the commutator, so that the rotating cutter will engage the next slot and the indexing device will release itself from such slot after entry by the cutter into the new slot whereby the commutator is free to rotate about its longitudinal axis `so as to accommodate itself fully to the cutter during the undercutting operation.

Other objects and advantages of this invention relating to the arrangement, operation and function of the related elements of the structure, to various details of construction, to combinations of parts and to economies of manufacture, will be apparent to those skilled in the art upon consideration of the following description and appended claims, reference being had to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

Referring to the drawings:

Fig. 1 is a perspective view from the right of the machine showing the driving connections; u

Fig. 2 is a perspective view from the left showing the loading mechanism;`

Fig. 3 is a plan view;

Fig. 4 is an elevational view;

Fig. 5 is an elevational view of a stop mechanism;

Figs. 6 to 9'inclusive are end elevational views of the indexing device;

Fig. 9A is a plan view of the indexing device;

Figs. l0 to 14 inclusive are elevational views partly simplified to show actuating means for indexingdevice; and t Fig. l5 is a perspective view of a detail related to the indexing device.

Referring now to the drawings, particularly .to Fig. 1, a

machine is shown incorporating the invention. The machine comprises a base member 20 adapted to form a guide for a reciprocatingmember 22 adapted to recipro-` cate an armature A longitudinally of the base member and under a relatively fixed rotating cutter K positioned above the commutator C ofthe armature in such a manner thatit undercuts the mica between the commutator segments as the armature is moved longitudinally along the base member. The armature A is removably heldby its shaft 24 on the reciprocating member 22v by manually manipulatable means to be described in detail hereinafter, so that an operator can position an armature in the machine for undercutting the mica be,- tween the segments of the commutator in an automatic operation after once being manually indexed by the op erator and, after completion of such undercutting opl eration, the armature can be removed by the operator and a new armature inserted for the beginning of a new cycle.

Since the commutator C has a predetermined number of copper segments separated by an equivalent number of rnica segments which must be undercut, it is essential for automatic operation of the machine that the reciprocating member 22 carrying the armature A, reciprocate the commutator C under the cutter K, so that the cutter enters each slot between tne commutator segments to undercut the mica. A special mechanism is provided with a control means, which will be described in detail hereinafter, to reciprocate the armature and its commutator a predetermined number of times to attain such end, after which the control means automatically stops the reciprocation, so that the operator may remove the completed armature and insert a new armature to begin a new cycle. For automatic operation, the new armature, after once `being lined up by the operator in the machine, a special indexing mechanism is provided which will also be described hereinafter under a special heading, which rotates the com-' K is free of the commutator, so that at the next reciprocation of the member 22, the cutter K can enter the next adjacent slot whereby all slots of the commutator may be consecutively engaged by the cutter to complete the undercutting of the mica therein.

The reciprocating mechanism and its control device yThe relatively-fixed rotating cutter K, which overhangs the .commutator C, rotates in the4 plane of the reciprocatory motion of the member 22, .so that it moves along the commutator slots, which are in substantially parallel juxtaposition with the shaft 24 of the armature, although it often occurs that a slight angularity is found therebetween, whereby, to have the cutter K follow the `slot between the commutator segments, a slight rotation vof the commutator is essential. The mechanism whereby this -is attained relates to the suspending means for the armature A which oats between live centers, so that the cutter K, which is tapered on its side, preferably to an included angle of 30 degrees, will exactly follow the mica between the commutator segments and will slightly .turn the armature and vits commutator about its longitudinal axis to compensate for any slight angularity in some `connnutators with the axis .of the shaft arising from faulty assembly of the commutator.

The cutter K is a small milling cutter rotated at relatively high speed by its shaft 26 journaled in a large bearing 28 xedly mounted with reference kto the bed 20 which is manually adjustable by any suitable means 29 to allow adiustment of the depth of cut in the undercutting of the commutator. justment by movement of bed 20 are well known in the art and will not be described in further detail. The back end of' the shaft 26 is provided with a pulley 30 which is beltdriven by an electric motor (not shown). The cutter K isl removably mounted on its shaft 26 by well known means to allow replacement thereof after being used lfor a time.

Mounted on the reciprocating members A,22 is a head stock 32 and a tail stock 34 which hold the armature shaft 24 between live centers as shown in Figs. 3 and 4, the tail stock 34 being provided with a manually-operable reciproeating portion 35 which allows the armature A to be inserted in operable position in the machine when in retracted position (Fig. 2) upon an adjustable V-block 36 cooperating with the laminated portion of the armature as shown in Fig. l with the shaft 24 positioned in opensided bearing 37. Whenthe reciprocating portion 35 is moved to operable position (Figs. 3 and 4) by manual manipulation of its locking toggle 35A, a spring 33 places a'bias against the end of the armature shaft to thrust the opposite end into the head stock 32 where it is heldin .a live center 39, a conical section being provided to facilitate the entry ofthe shaft therein. In this manner, the armatureA is inserted in the machine with its shaft 24 in substantially horizontal position, so that the commutator is held in predetermined position with reference to the cutter K to: give the desired depth of undercut of the mica between the segments thereof, and also held in freely rotat-V able relation about the axis of its shaft whereby the commutator is free to rotate so as not to bend the cutter K but allows the cutter to follow the micas uniformly even if canted'without cutting into an adjacent segment in the event the commutator is not accurately assembled. The slot of the commutator thereby always remains in the plane of rotation of the cutter K.

The headstock 32 and the tail stock 34 are conveniently attached to the reciprocatingmember 22 by bolts 42, so that both will move with the member 22 when it is reciprocated by a connecting pitman 44 attached thereto at the left end (Fig. l) by pin 46 (Fig. 2). The pitman 44 is`oscillated by crank pin 48 mounted eccentrically on face plate 58 mounted on a rotating shaft 52 journaled irl-bearing S4. At its end distal from the face plate 50, the shaft 52 is provided with a friction clutch 56, preferablyincluding a leather-faced disk splined to the shaft resiliently urged (adjustable) against a driver plate belt The mounting of the cutter K and its adn driven by a separate electric motor (not shown), so that a flexible drive relation is established which will allow the motor to overrun when the face plate S0 is stopped at a predetermined position whereby the reciprocating member 22 is located at a predetermined position for the removal of the completed armature and the substitution of a new armature by the operator for the initiation of a new cycle of operation. The mechanism to accomplish such end will now be described.

The stop mechanism for the reciprocating member 22 comprises a lug 58 extending'from the edge of face plate 59, as is shown in Fig. 5, the face plate rotating in a counterclocltwise direction, so that the lug contacts the end of a pivoted lever 6l? under control of the armatures of a pair ot' solenoids 62 and 64 acting on the lever 60 on opposite sides of its pivot. A spring 66 is provided to bias the lever into the path of the lug 58, being aided by the solenoid 64, while solenoid 62 pulls the lever end out of the path of the lng against the bias of spring 66. The cooperative relation between the lug and lever stops the reciprocating member 22 at the predetermined point required, the friction clutch 56 slipping for a moment while the driving motor overruns.

The `driving motor for the reciprocating means and the solenoid 64 are alternately controlled by a single throw, double pole switch 68 (Figs. l and 2) mounted adjacent the solenoids 62 and 64, the switch being operated by a spring-actuated plunger 7l) reciprocated by a pivoted lever 72 having a roller 74 on its end which is positioned in the path of a pivoted lug 76 mounted on a relatively-xed rotatable ratchet wheel 78 to extend beyond its periphery. The p'ivoted lug 76 moves between stop pins 80 whereby the switch 68 is momentarily actuated by the lug 76 to deenergize the driving motor and energize the solenoid 64 for a `short period and thereafter clears itself to allow initiation of a new cycle. A manual switch 82 (Fig. 2) again energizes the motor and also solenoid 62 for the initiation of the new cycle of operation on a new armature and its commutator.

As pointed out hereinbefore, for the automatic operation of the machine, it is essential that the reciprocating member 22 reciprocate once for every slot in the commutator, whereby the cutter K may enter each such slot to perform the undercuttng of the mica insulation. This sequential operation is controlled by switch 68 after the new cycle is started lby the operator actuating the manual switch 82 which starts the motor and energizes solenoid 6.2. The solenoid 62 is then continuously energized until switch 68 is again actuated by lug 76. This occurs after the ratchet wheel 78 rotates a complete revolution, being moved step by step by spring linger 84 which reciprocates with themember 22 and actuates the ratchet wheel 78 one step when it moves to the right therewith (Fig. 1). The ratchet wheel 78' has the same number of teeth as 1' there are slots in the commutator C. Upon completion of a complete revolution of the ratchet wheel 78, the lug 76 will again actuate the switch 68 to momentarily energize solenoid 64 to simultaneously move the lever 60 so that the lug 58 contacts its end to stop the reciprocation of the member 22 at the predetermined point. The commutatorhaving been completely undercut during the cycle, the operator removes it and inserts anew one and actuates manual switch S2 to begin a new cycle of operation.

ComnrumtorV indexing device bygaligning an indexing finger 90 with the mica in tbe M7 next adjacent slot as a positive guide, until the cutter enters the aligned slot to begin the cutting operation whereat the finger 90 is removed upwardly by mechanisms to be described hereinafter to release the commutator, so that it may rotate on the live centers to accommodate itself to the cutter which then closely follows adjacent the segment sides even though they may be slightly canted. The cutter then makes 'a complete excursion, being moved in and then reversing and moving out of the slot again as controlled by the eccentric 48 and the pitman 44 moving the base 22 as already described.

For convenience and clarity in description, the separation between the adjacent commutator segments in which the mica insulation is positioned and which is to be undercut by the herein described machine, is called a slot, even though the mica before undercutting may extend beyond the perimetrical surface of the commutator.

On the return movement of the base 22, which moves the cutter K back out of the slot, an indexing mechanistn is being energized which prepares to move the commutator one slot circumferentially by engaging the finger 90 behind the cutter K in the slot which has just been cut away, so that when the cutter K is clear of the slot, such circumferential movement (counterclockwise Fig. 6) occurs, whereby the next adjacent slot is aligned with the cutter K to be engaged thereby when the cutter is caused to make another excursion relative to the commutator to cut away the mica therein. After the cutter enters the new slot, the finger 90 will again be released to free the commutator, so that it may again accommodate itself to the cutter. The mechanisms to attain this result will now be described.

The indexing device comprises a movable laterally-extending arm 92 which controls the movements of the finger 90, already referred to, cooperating with elements in fixed position mounted on a bracket 94 afixed to the base member whereby the various movements of the finger 9i) are controlled and actuated in timed relation with the movement of the commutator C as reciprocated by the member 22. The arm 92 is brazed to the live enter 39 through a collar as shown in Fig. 4 and is rotatable about the axis of rotation of the armature shaft 24, being biased for rotation in a counterclockwse direction (Figs. 6 to 9) by spring 96 active between a downwardly extending pin 98 affixed to the arm 92 and an anchor pin 100 affixed to the member 22 (Fig. 9). To limit the rotation, a stop bar 102 is affixed to the head stock 32 to underlie the arm 92, an adjustable stud 104 (Fig. 2) being provided therein to contact the bar 102 to provide an adjustment. The arm 92 is freely rotatable with reference to the armature shaft which, in turn, is freely rotatable in the live center 39 as already-described.

Mounted on the rotatable arm 92 on pivot pin 106 is a V-shaped member 107, on the upper arm of which is attached finger 90 by v a suitable-means such as screws, and the lower arm, being relatively shorter than the upper, is provided with a roller 108 adapted to cooperate with relatively fixed camming members .therebelow as will be described further hereinafter. The member 107 is urged clockwise (Figs. 6 to 9) about its pivot pin 106 by compression spring 110 acting between suitable abutments as shown, whereby the linger 90 is urged toward the commutator below it, and roller 108 is urged toward the camming members below it. Spring 110 is relatively weak as compared to larger main spring 96 active on arm 92 and will be overcontrolled by its action on the machine elements.

On the forward end of the arm 92 a roller 112 is provided, as seen in Figs. 6 to 9, and also Figs. 10 to 14, which cooperates with a pivoted cam member 114 positioned in relative fixed relation on the bracket 94 by arm 94A `and adapted to move about pivot 116. VA bias is provided by spring 118 to rotate the cam 114 clockwise about the vpivot 116, the spring being conveniently positioned thereon, as shown in Fig. 3, whereby the lower end of the cam member is urged against an adjustable stop 120 which holds it in substantially upright position as shown in Fig. 12. In Figs. l0 to 14 inclusive, the interaction of the roller 112 and the cam member 114 is shown by various steps, whereby the arm 92 is raised and lowered in timed relation with the movements of the commutator C to actuate the indexing device during the return stroke which backs the cutter K out of the commutator slot already undercut, and prepares the relation between the cutter K and the commutator C for the initiation of a new cycle in the next adjacent slot of the armature.

Referring to Figs. 9 and l1, the cutter K is in undercutting position in a slot of the commutator C, with the cutter being' advanced into the slot by the advance of the commutator C by movement of the member 22 as shown in Fig. ll. In this figure, the roller 112 is dellecting th'e cam 114 against the bias of the spring 118, while the .stronger spring 96 holds the arm against its stop 104 cooperating with the underlying bar 102 and finger 90 is freed from the underlying commutator slot against bias of spring 110 by contact of roller 108 with a cam surface `122 (Fig. 9) aixed on the bracket 94. The cam surface 122-is positioned in a relation with the cutter K, so that just after the cutter K enters a new commutator slot just adjacent to the newly out slot engaged by the finger 90, tire roller 10S will engage the front face of the cam surface l2?. to rotate the V-shaped member 107 about its pivot 196 against the bias of spring 110, just sufficient to cause the finger 9@ to disengage its slot and free the armature and its commutator to rotate about its shaft 24 held in the live centers, whereby the commutator can accommodate itself to the cutter K to allow it to follow the slot accurately even though slightly canted.

The deflection of the cam member 114 in a counterclockwise direction by the roller 112 begins already with the parts as shown in Fig. lO where the cutter K is adjacent its maximum retarded position entirely free of the commutator where a new commutator may be positioned after the completely undercut one with its armature is removed if so desired and the machine elements are in the required relation. The deflection continues as the cutter K moves into cutting reiation with the slot, as shown in Fig. il, where an intermediate position of the coacting parts is shown, and then continues until the cutter K is in its maximum advanced position, shown in Fig. l2, having just completed undercutting the slot of the commutator, and, in the meantime, the roller 112 has overrun the cam element 114 which is returned to its stop 120 by the bias of' spring 118 and is ready to perform its function on the return stroke of the cutter K when the roller 112 reverses itself as shown in Fig. 13. The roller .112 here contacts the reverse side of the cani member 114 from that shown in Figs. l0 and l1, and since the stop 12u prevents clockwise rotation of the cam member 114, the roller 112 begins to displace the arm 92 upwardly against the bias of 'spring 96, which prepares the indexing mechanism to position the finger into the slot engaged by the cutter K so as to move the com mutator about its shaft one slot distance after the cutter is clear, so that the cutter, on its next excursion, will engage the next adjacent slot for the purpose of undercutting the mica therein.

The front arcuate face 114A is engaged by the roller 112 and lifts the arm 92 upwardly (clockwise Figs. 7 and 8) which advances the finger 90 into the plane ot` the cutter K so as to overhang the slot of the commutator just undercut by the cutter. The lifting of the arm 92 carries with it the Vshaped member carrying the finger 90 and clears the roller 108 from the cam surface 122. However, the finger 90 is not allowed to contact the commutator face as urged to do by the bias of spring by latch element 124 engaging a bar 126 at the distal lend of the arm 92 immediately above the roller 112 as is best seen in Figs. 6to 9 inclusive.

i amantes l The baraz126 isatfached@to.lthewfshapedimembert-IO' tf-theo` completed :armature sremovedffby"thesoperator .rand isf-adapted to' projectloutwardIy,beyond the pit/68106 1:and aenewe'onwinsertedA landeeclosingvthe togglej'Itlie to cooperate withwthelatch1elementL24,iwhich isf pivoted f-ope'ratonactuate the frnanual lpu'shf fbuttoi`i82'lwhch' starts :1 at :theafarwendofwtherarm:92 vto"entendeupwardlyas a ,newvcycleofl'operationby simultaneouslyf.energizing :showin-'randv isfurged torotatefclockwise about Aits pivot fielecttomagnetzandthefmotor(not shown): driving .face ruby:tensionrspring.12Slacting1-between itcnd a suitable plate-60.

b anchorson'fthe "arm1;92. The latch :element- 124 is: pro- 'i lhe purpose of the safety/device actuatedrbythe retracpvidedinvith' anv overhange124Aowhich; engages .the :end ,iomhnovement to right in:2Fig2)'"of -rod1f40 is to. raise v oxthe bar1126 to preventclockwise rotationl ofthe memfzfther'actuatjngffngera ofthe indexingadevice a substanr-berz107 about tits pivot V1"-106.;and.;,then-:by: prevents the'llo vtiztldistanceftotgivezample clearanceitolallowhe operator mfmgerf90ffromicontactingthe.surfacel ofthe commutator to remove .theuc'ompletelya:undercutrarmaturefrom -the C until the-latch 24: is disengaged. A cam surface 'machineizand;tolinsert a `new;arrnatureifor aaneWfcycle 124B is provided onvtheupperend'of- .the latch .element :'of-noperation..rzsReferringlto:Fig 15;.: the' mechanism. is ,124*(Fig.` 10) which is oblique to the axislofrthecomshowmimsirnplified formiwherebyzthis'result iszattained.

.imntaton C andtacesstoward: the-i cone-.shaped end 0h15 rflhe-rodtf40 isfadjust'ably attacheditosthe. toggle 35A cani pinr136 vwith'which it -cooperatesto rotate ythe latch -by--an earwSB which isxengagedeby 'a pair; ofti1ock,;nuts

:.elementx124vin a counterelockwise..direction about its 40B in threadedurelationfon:ithefzrod 40*asfbest' seen .-pivot: to release bar 126 from. the overhang .1.24A, so errFig. 2.2The rod l40 is held for longitudinal-movement ..that-.inger90` drops .down .intothe commutator slot just by-journals^ 46l affixed tofthe reciprocating memben22 in ,fusidercut, by the bias of spring 110.y This action is shown-20 any suitable ymanner Adjacent the bracket'94,` lrod'40 .in Figi 8, where..the roller 112 is .onrthe apex of cam -Y isprovidedewith a-shoulder:Mitel-whichiterrninates` atfthe member '.114 -.(see;Fig.-l4). and roller=1l08, as a conse- :-CliStal -efld=it0 a-latefally maleetingffeamfmemberl40C .quence, is free from cam surface 122.4 The cutter K- clears :which is .adapted t0 COOPeFate IWith roller '108 t0 liftfthe v thecornmutatorslot just after the finger 90,-drops into V-shaped armllabout-its pivot-106 and, in llllrl, flgel' the slot which the cutter has just undercut. .25 f90 by a turning in fawcounterclockwise. direction (Fig6).

Thecam pin 13d is adjustably fmountedjn horizontal jThelatch.mernber-f124 is clearedto-allowsuchxmove- .position parallel tothe axis of the commutator in a por- AInerltgil/'a PVOted level' i149 (Fig. 3), the lOWer end 142 tion 9450i the fxebrackgr 94 `(Fig9) and projects `of .which isbifurcated to cooperatef( Fig.-. 15) with the toward theheadstock 32 at such aijuxtaposition as to .-Sh011ldel'4d,--S0-tl1at,-=aSthe-T0d -40 iS Pulledl l0 the engagecam. face 124B when it is raised to its'highest posie30 v.lglltiFig .15)iby'tl1e'imat1llal actuation 0f the toggle tion bythe roller-.112 .riding over the apex of cam 114 .35.A,fthe lever :1140, is, rotated,counterclockwise. aboutiits "(Figsi. 10 and l4).to rotatey the arm 92 in a clockwise Centrally-located pivot 144 mounted on the bracketrpordirection. 'F.The, parts-come into .,contactual relation, ti0n94B to. actuate a spring-biasedpin.146.mounted in namely, cam pin 130. and -cam.t'ace 124B through the an aperture. inthe bracket portion V94BV in aposition to rotation of the ami, 92 about the live gente.;-l39jby the 35 contact thelcamfacelMB. ofthe latch 124 to thrust it Lactiorrof the cam 114 as .alreadydescribed'and also by outwardly@(COUHteClOGkWSe Fig 5).aI1Cl therebyneleal' Athe longitudinal juxtaposition' of the arm 92 withreferencc .the free end 0f 'Clie bal! 12.6; aHdallOW -Cam- 40C tOfl'aiSe to the fixed bracket 94 as shown in Figs, land 8, the .iinger90 clearfof4 the commutatonso ,that it can be As the cutter K approaches its maximum retarded posi- .removed and a new one 'substitutedtion (Fig. .10), the roller 112 drops over-.t0 the bagks 40 .When the operatoragain closes toggleSSA, as already of the carn 114 and allows spring. 96- to. rotate thearm CleSCril'Jetl.fa'llill iS. moved te the left*y (Fig l5) t0 free "92 in a counterclockwise direction (Fig..9) from its posi- Ollef'IS from CaIC, allflvleleaSeYPiil 146; by Tetufll tion shown in Fig. S. Due. to the factthat. nger ..90 "0f`levef140 t0 HOfmal POSitiOIi by the-SPI'illgfbiaS 011 the has dropped into the commutator slot which. has just been PiIlf This: 'allOWS the latch 124 t0. again restrain bal' 125 undercut, the arm 92 and the. commutator are locked andl'aftei' thefOPe'Yatl has manually aligtled the. llllge'l` 90 together, so that the commutatorwill be rotatedsimul- With a mica. .Whel' the Cutter" K enters into" thtl'St taneously. to align the next adjacent slotof the commu- "SlOt'Of' the new( armature, 0lle`f`108 again Contacts the ,.tator in a clockwisev direction with the Acutter K, so .that "fIOHtfaCe''Of Cam faCe`122`WhiehCaUSeS the latel'l 124 l0 it may, in its turn, be undercut with. the next excursion lolly-engage he'end of bar'^126.`"".'l.`he machine thenconof the cutter. 5@ "tinues"y toope'rate 'through'. its normal :cycle as`.already The face plate 50 continues to rotate .untilstopped by "deseribed vactuation of switch 68 as controlled by ratchet wheel'78 i It iS t0 bemldetelad that the` abOVe detailed deSfiP and lug.. 76 thereon, so that a commutator once placed -tionothe present invention is intended to disclose an 4in themachine will be completely. undercut automatically, "eml'lbdlmetlt thereof t0' those 'Skilled in the aft, but that and-after the substantial completion of oneexcursion of Ztheinvention' iS 110? t0 lle construed alimite'd iilitS; aP

the cutter K .for a slot (Fig. 6), .the cutter will. immeyiplitfatiofi"tti"'llledetailsieff'COllStl'iletiOIl'andafrailgeillelt diately begin a new excursion in ,the nextconsecutive slot 1f-Parteiillustrated" iti thfaecempanyilg flfaltillg Since ofthe. commutator with a repetition'jof. movement of. the 'ithe' iHVentiOil iSeaP'able'iOf beingpfaetleed and Carried elements of the machine as set forthhereinbefore. This 01min VariousWaYSiWithOUtdePal'tingffOUi the' SPiI'ifUf will continue until the lug 76 actuates switch 68 and stops G0 Ltllefinvention-Tile ianguage'uaed il"tl1e SPeCilleatiOIl l'e- .the face plate 50 by having lug 58 thereon abut against latingtofthet-0Peati0I1anfi'fUUCtiOD 0f' 'ther elements' 0f -the end 0f lever 60, which is pulled upbyiheispring 66 irtheinve'ntion is-ernployed-for,purposes of-description and and the' electromagnct 64.` Electromagneti62:.which is "not ofiimitatianfand it iSmOt-inte'lldedt`liI1it'tl'1e`SC0Pe energized through. the whole .undercutting-cycleiof the Ufhmf'iliowilgciaim's bewind"'tlle'TeqllirementS"offthc commutator topullthe lever 69 downwardfto-clear lug 65 :"Pnorart' '58 during reciprocation of pitman` 44 isdeenergized what isiidailpedi when electromagnet 64 is energized as described above. li In adev'lcex Gimme das? descnpedimeanl to 'sus' Whenthe commutator is completely undercut yand the pend the commutator upon s longltudmal ams awotatabl:cuttergimeans: to cause relative movement of'the 4.tlomnmtatore withy reference to.` :the` cutterliwhereby -the .eutterrrnayfenter thefslots ofihe. commutator to undercut -machine stops automatically, .an operator.'releasesvthel toggle 35A which retracts;the center from' there'nd'of 170 the Shaft. 24 and also YetTaCtS in the .Same directionfod Athe insulation;.itherein.saidrcutterff'having:"itsplanedof 140;.to. actuate a safety .device-relative to` ther tingeril jmlatiwh movement 512mg;` 3,162 loniltudinaf :tofu-:libc i0/ Pfoteetl ltflOm 4ITleCllaaiCal abuse by" the jOPelatOI commutator,.autorrlaticindexing ineans including 'ar-*finger :white-:he: iszremovingv the completedari-nature'orfsnbsti-v voperable byia camm'echanis'rn tocngagethecommutator toting a new. one*` With the 'toggleSSA in 'open'positiom 0- the'slot just undercut substantially simultaneously with the disengagement of the rotatable cutter with the slot to rotate the commutator one slot distance while the cutter is clear of the commutator so that the cutter enters a new slot upon its next engagement during its relative reciprocatory movement with the commutator, said indexing means disengaging from the commutator by a second independent cam mechanism while the cutter is undercutting the new slot whereby the commutator is freely rotatable to accommodate itself to the cutter so that the slot portion being undercut is always maintained in the plane of said cutter, and means for automatically stopping the device after the commutator has had all of its slots undercut.

2. In a device of the class described, means to suspend the commutator upon its longitudinal axis, a rotatable cutter, means to cause relative movement of the commutator with reference to the cutter whereby the cutter may enter the slots of the commutator to undercut the insulation therein, said cutter having its plane of relative movement along the longitudinal axis of the commutator, indexing means in fixed relation with the commutator operable by a cam means actuated by said relative movement to engage the commutator in the slot just undercut ajdacent its outer end just before the rotatable cutter clears the slot to rotate the commutator about its longitudinal axis one slot distance while the cutter is clear of the commutator whereby the cutter enters a new slot upon its next engagement with the commutator, a second cam means operated by said relative movement to disengage the indexing means from the commutator while the cutter is undercutting the new slot whereby the commutator is freely rotatable to accommodate itself to ,the cutter so that the slot portion being undercut is always maintained in the plane of said cutter, and means for automatically stopping the device after the commutator has had all of its slots undercut. Y

3. In a device of the class described, means to suspend a commutator for rotation upon its longitudinal axis, a rotatable cutter, means to reciprocate the commutator longitudinally with reference to the rotatable cutter, said rotatable cutter having its plane of rotation in the longitudinal axis of the commutator and in the plane of the reciprocation of the commutator whereby the cutter may enter the slots of the commutator to undercut the insulation therein, automatic indexing means suitable for initial manual adjustment engaging the commutator slot just undercut to hold the commutator under control while the cutter is free therefrom, cam means actuating the indexing means to rotate the commutator one slot distance while the cutter is free whereby the cutter enters a new slot upon its next engagement with the commutator, a second cam means to disengage the indexing means from the commutator while the rotatable cutter is undercutting the new slot, and means to automatically stop the reciprocation of the commutator after all the slots of the commutator have been undercut.

4. In a device of the class described, means to suspend the commutator upon its longitudinal axis, a rotatable cutter, means to cause relative movement of the commutator with reference to the cutter whereby the cutter may enter the slots of the commutator to undercut the insulation therein, said cutter having its plane of relative movement along the longitudinally axis of the commutator, indexing means including a contact finger suitable for initial adjustment to engage the commutator in the slot just undercut just before the rotatable cutter clears the slot to rotate the commutator by a cam actuated by the relative movement one slot distance while the cutter is clear of the commutator whereby the cutter enters a new slot upon its next engagement with the commutator, said indexing means disengaging from the commutator by the action of a second independent cam while the cutter is undercutting the new slot whereby the commutator is freely rotatable to accommodate itself to the cutter means so that the slot portion being undercut is always main- 10 tained in the plane of said cutter, means for automatically stopping the device after the commutator has had all of its slots undercut, and a third cam capable of manual manipulation means to retract the indexing means while the commutator is removed from the device.

5. In a device of the class described, means to suspend a commutator for rotation upon its` longitudinal axis, a rotatable cutter, means to reciprocate the commutator longitudinally with reference to the rotatable cutter said rotatable cutter khaving its plane of rotation in the Vlongitudinal axis of the commutator and in the plane of the reciprocation of the commutator whereby the cutter may enter the slots of the commutator to undercut the insulation therein, automatic indexing means including a finger engaging the commutator slot just undercut to hold the commutator under control while the cutter is free therefrom, cam means operable by the return movement of the commutator actuating the indexing means to rotate the commutator one slot distance while the cutter is free whereby the cutter enters a new slot upon its next engagement with the commutator, a second cam means operable by the forward movement of the commutator to disengage the indexing means from the commutator while the rotatable cutter is undercutting a new slot, means to automatically stop the reciprocation of the commutator after all the slots of the commutator have been undercut, and manual means to disengage the commutator and to retract the indexing means while the commutator is removed from the device.

6. In a device of the class described, means to suspend acommutator for rotation upon its longitudinal axis, a rotatable cutter, means `to reciprocate the commutator longitudinally with reference to the rotatable cutter said rotatable cutter'having its plane of rotation in the longitudinal axis of the commutator and in the plane of the reciprocation of the commutator whereby the cutter may enter the slots of the commutator to undercut the insulation therein, automatic indexing means mounted on the reciprocating means engaging the commutator slot just undercut adjacent its leading end to hold the commutator under control while the cutter is free therefrom, fixed cam means actuating the indexing means during reciprocation to rotate the commutator one slot distance while the cutter is free whereby the cutter enters a new slot upon its next engagement with the commutator, a second fixed cam means to disengage the indexing means from the commutator while the rotatable cutter is undercutting the new slot, and means to automatically stop the reciprocation of the commutator after all the slots of the commutator have been undercut.

7. In a device of the class described, means to suspend a commutator for rotation upon its longitudinal axis, a rotatable cutter, means to reciprocate the commutator longitudinally with reference to the rotatable cutter said rotatable cutter having its plane of rotation in the longitudinal axis of the commutator and in the plane of the reciprocation of the commutator whereby the cutter may enter the slots of the commutator to undercut the insulation therein, automatic indexing means rotatably mounted on the same axis as the commutator and reciprocable therewith engaging the commutator slot just undercut adjacent its leading end to hold the commutator under control while the cutter is free therefrom, fixed cam means cooperating with a portion of the indexing means actuating the indexing means during the return movement of the commutator to rotate the commtuator one slot distance while the cutter is free whereby the cutter enters a new slot upon its next engagement with the commutator, a second fixed cam means cooperating with another portion of the indexing means to disengage the indexing means from the commutator during the forward movement of the commutator while the rotatable cutter is undercutting the new slot, means to automatically stop the reciprocation of the commutator after all the slots of the cornmutator have been undercut, and manual means to release the commutator is being removed from the device.

8. In a device of the class described, including a recipro-v cating mounting means for mounting a commutator'on its longitudinal axis for free rotation thereabout and a tapered rotatable cutter adapted by relative movement with reference to the commutator along its longitudinal axis to undercut the insulation in the slots of the commutator, characterized by an indexing means including a finger actuated by a first independent means to engage thecommutator in a slot just undercut while the rotatable cutter isV still engaged in the slot, said finger being then actuated by a second independent means to rotate the commutator one slot distance while engaged with a commutator slot when the cutter is clear of the commutator so that the cutter may enter a new slot in its next excursion, saidnger being then actuated by a third independent means for disengaging the finger from theslot when the rotating cutter engages the new slot so that the `cornmutator may rotate to accommodate itself to the plane of the cutter solely by the interaction of the sides of the tapered cutter and the slot sides.

'9. In a device of the class described, including a reciprocating mounting means for mounting a commutator on its longitudinal axis for free rotation thereabout and a tapered rotatable cutter adapted by relative movement with reference to the commutator along its longitudinal' axis to undercut the insulation in the slots of the commutator, characterized by an indexing means actuated by said relative movement including a iinger adapted to engage the commutator in a slot just undercut by the action of a first cam means while the rotatable cutter is still engaged in the slot, said finger being then operated by a second cam means to rotate the commutator one slot distance while the cutter is clear of the commutator so that the cutter may enter a new slot in its next excursion, said iinger being then operated by a third cam means to disengage the finger from the slot when the rotating cutter engages the new slot so that the commutator may 12 rotate Ito accommodate itself to the plane of the cutter solely by the interaction of forces 4between vthe cutter and the slot sides.

10.l In a device ofthe class described, including a reciprocating mountingv means for mounting a commutator on its longitudinal axis for free rotation thereabout and a' tapered rotatable cutter adapted by relative movement with reference to the commutator along its longitudinal axis to undercut the insulation in the slots of the commutator, characterized by an indexing means actuated by said relative movement of the parts including a finger adapted to move tangentially to engage the commutator in a slot just undercut by the action of a cam means' actuated by said relative movement while the rotatable cutter is still engaged in the slot, said finger ofthe indexing means being then operated by a second cam meansv also actuated by said relative movement to rotate the cornrnutator one slot distance while the cutter is clear of the commutator so that the cutter may enter a new slot in its next excursion, said finger of the indexing means being then actuated by a third independent cam meansactuated by said relative movement to disengage the finger from the slot when the rotating cutter engages the new slot so that the commutator may rotate freely to accommodate itself to the plane of the cutter, and means to automatically stop the device after all the slots of the com,- mutator have been undercut.

References Cited in the iile of this patent UNITED STATES PATENTS 259,043 Reynolds June 6, 1882 328,075 Smith Oct. 13, 1885 906,160 Reinen Dec. 8, 1908 2,061,398 Green Nov. 17, 1936 2,180,771 Poole Nov. 21, 1939 2,352,278 Manley June 27, 1944 2,372,304 Volzka Mar. 27, 1945 2,519,653 Haywood Aug. 22, 1950 

